Shelly Peiken is an American songwriter who is best known for co-writing the US No. 1 hits "What a Girl Wants" and "Come On Over Baby" by Christina Aguilera the US No. 2 hit "Bitch" by Meredith Brooks, "Almost Doesn't Count" by Brandy, "Who You Are" by Jessie J, and "I'm A Mess" by Bebe Rexha. She has also written for or with Britney Spears, The Pretenders, Natasha Bedingfield, Keith Urban, Rebecca realize, Celine Dion, Cher, Reba McEntire, Jessie J, Miley Cyrus, Ed Sheeran, Aaliyah, Selena Gomez, Idina Menzel and Demi Lovato and has had hundreds of songs licensed for TV and film.